JPH10139963A - Resin composition - Google Patents

Abstract

(57) Abstract: (a) One or more polymer blocks A comprising a polystyrene resin, (b) a polyolefin resin and (c) an aromatic vinyl compound, and a conjugated diene compound, A resin composition comprising a hydrogenated block copolymer having at least one polymer block B in which 70% or more of carbon-carbon double bonds derived from a conjugated diene compound is hydrogenated, and having a hydroxyl group at a terminal. When the weights of (a) a polystyrene resin, (b) a polyolefin resin, and (c) a hydrogenated block copolymer in the resin composition are defined as W _A , W _B , and W _C , respectively. 005 ≦ W _C / (W _A + W _B + W _C ) ≦ 0.25. [Effect] A molded article having excellent impact resistance and chemical resistance is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition, and more particularly to a resin composition comprising a polystyrene resin, a polyolefin resin and a specific hydrogenated block copolymer having a terminal hydroxyl group.

[0002]

2. Description of the Related Art Polystyrene resin is a highly rigid resin having excellent moldability and secondary workability, and is widely used in applications such as office equipment, audio equipment, household electric appliances, and interior and exterior materials of automobiles. However, there is a problem that it is inferior in impact resistance and chemical resistance.

[0003] On the other hand, polyolefin resins are excellent in impact resistance and chemical resistance, and are used in a wide range of applications such as automobiles, vehicles, buildings, electric parts, and daily necessities. It is inferior to the above.

[0004] Attempts have been made to blend a polystyrene-based resin and a polyolefin-based resin to obtain a composition having the advantages of both, and excellent in moldability, secondary workability, impact resistance and chemical resistance. Was. Among them, when a hydrogenated product of a specific block copolymer consisting of an aromatic vinyl compound such as styrene and a conjugated diene compound such as butadiene or isoprene is used as a compatibilizer, the compatibility between polystyrene resin and polyolefin resin is improved. Provides a relatively good and uniform composition.

[0005]

However, even when a hydrogenated product of a specific block copolymer comprising an aromatic vinyl compound and a conjugated diene compound is used as a compatibilizer, impact resistance and chemical resistance are not improved. In view of the above, the properties of the obtained resin composition are not always satisfactory. Thus, an object of the present invention is to newly provide a resin composition containing both a polystyrene-based resin and a polyolefin-based resin and having excellent impact resistance, chemical resistance, and the like.

[0006]

According to the present invention, the above object is achieved by providing at least one polymer block A comprising (a) a polystyrene resin, (b) a polyolefin resin and (c) an aromatic vinyl compound. And a conjugated diene compound, wherein at least 70% of the carbon-carbon double bonds derived from the conjugated diene compound are hydrogenated.
A resin composition comprising a hydrogenated block copolymer having at least one hydroxyl group and having a hydroxyl group at a terminal, wherein (a) a polystyrene resin, (b) a polyolefin resin, and (c) water in the resin composition. the weight of the hydrogenated block copolymer each W _a, W _B, when formed into a _{W C, 0.005 ≦ W C /} (W a + W B + W C) resin composition which is a ≦ 0.25 Is solved by providing.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the polystyrene resin (a) used in the present invention, known resins are used without any particular limitation. Specific examples thereof include homopolymers of styrene,
Impact-resistant polystyrene (high impact polystyrene (HIPS)) obtained by graft-polymerizing a styrene monomer onto a diene rubber, a copolymer of styrene with α-methylstyrene, chlorostyrene, etc., a styrene monomer with unsaturated nitrile, α, A copolymer of a vinyl monomer such as β-monoolefinic unsaturated carboxylic acid ester, or a styrene monomer and the vinyl monomer described above as a diene rubber, an acrylic rubber containing an unsaturated group, chlorinated polyethylene, ethylene-vinyl acetate An impact-resistant resin obtained by graft-copolymerizing a copolymer or the like may be used. The polystyrene resin (a) may be used alone or in combination of two or more.

As the polyolefin resin (b) used in the present invention, known resins are used without any particular limitation. Specific examples thereof include low-density polyethylene, medium-density polyethylene, high-density polyethylene, and polypropylene. , Polybutylene, ethylene / α-olefin copolymer, and the like. Here, as the α-olefin, propylene, 1-butene, 2-methyl-1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-
Decane, 1-octadecane and the like can be mentioned. The polyolefin-based resin (b) may be used alone or in combination of two or more.

The hydrogenated block copolymer (c) used in the present invention comprises at least one polymer block A comprising an aromatic vinyl compound and a conjugated diene compound, and is derived from the conjugated diene compound. Is a hydrogenated block copolymer having at least one polymer block B in which 70% or more of the carbon-carbon double bonds are hydrogenated and having a hydroxyl group at a terminal, for example, represented by the following formulas Are included.

(AB) k-OH (BA) 1-OH A- (BA) m-OH B- (AB) n-OH (wherein A is a polymer block A , B represents a polymer block B, k, l, m and n each represent an integer of 1 or more, and OH represents a hydroxyl group.) Here, the polymer block in the hydrogenated block copolymer (c) A and the number of repeats k, l, m and n of the polymer block B
Can be arbitrarily determined, but is usually 5 or less. The hydrogenated block copolymer (c) may be used alone or in combination of two or more.

In the hydrogenated block copolymer (c),
The content of the aromatic vinyl compound is not particularly limited.
It is preferably from 0 to 80% by weight, more preferably from 15 to 70% by weight.

The aromatic vinyl compound constituting the polymer block A in the hydrogenated block copolymer (c) includes:
For example, styrene, α-methylstyrene, o-, m- or p-methylstyrene, 4-propylstyrene, 2,
4-dimethylstyrene, vinylnaphthalene, vinylanthracene and the like. Of these, styrene and α-methylstyrene are preferred. The aromatic vinyl compounds may be used alone or in combination of two or more.

The conjugated diene compound constituting the polymer block B in the hydrogenated block copolymer (c) includes, for example, 1,3-butadiene, isoprene, 2,3
-Dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and the like, among which isoprene and 1,3-butadiene are preferred.
The conjugated diene compounds may be used alone or in combination of two or more.

The structure of the polymer block B in the hydrogenated block copolymer (c) is not particularly limited.
There is no particular limitation on the content of the bond or 3,4-bond.

The bonding mode of the polymer block A and the polymer block B in the hydrogenated block copolymer (c) is linear,
It may be branched or any combination thereof.

In the hydrogenated block copolymer (c), the hydroxyl group may be located at any of the terminals of the polymer block A and the polymer block B. It is preferably located at the end, more preferably located at the end of the styrene block. The content of such terminal hydroxyl groups is preferably 0.5 or more, more preferably 0.6 or more per molecule of the hydrogenated block copolymer (c).

The number average molecular weight of the hydrogenated block copolymer (c) used in the present invention is not particularly limited, but is usually from 30,000 to 500,000.

As a method for producing the hydrogenated block copolymer (c), a known method is used without any particular limitation.
The following anionic polymerization method can be used. That is, in an inert organic solvent such as n-hexane or cyclohexane using an alkyl lithium compound or the like as an initiator, an aromatic vinyl compound and a conjugated diene compound are sequentially polymerized,
After the addition of ethylene oxide or propylene oxide when the desired molecular structure and molecular weight is reached,
Alcohols, carboxylic acids, compounds containing active hydrogen such as water are added to terminate the polymerization, and the obtained block copolymer is treated with an alkyl aluminum compound in an inert organic solvent such as n-hexane or cyclohexane. cobalt,
In the presence of a hydrogenation catalyst such as a Ziegler catalyst made of nickel or the like, a reaction temperature of 20 to 150 ° C. and a hydrogen pressure of 1 to 1
In this method, hydrogenation is performed under a condition of 50 kg / cm ² .

The hydrogenated block copolymer (c) used in the present invention has a carbon-carbon double bond derived from a conjugated diene compound in the polymer block B from the viewpoint of compatibility with the polyolefin resin (b). It is necessary that 70% or more be hydrogenated. The carbon-carbon double bond derived from the conjugated diene compound in the polymer block B is
Preferably, 80% or more is hydrogenated, and 90%
% Or more is more preferably hydrogenated. The hydrogenation rate of the carbon-carbon double bond derived from the conjugated diene compound in the polymer block B of the hydrogenated block copolymer (c) can be determined by an iodine value measurement, an infrared spectrophotometer, nuclear magnetic resonance, or the like. The amount of carbon-carbon double bonds in the polymer block composed of the conjugated diene compound before and after hydrogenation can be measured, and the amount can be calculated from the measured value.

In the resin composition of the present invention, the composition ratio of the polystyrene resin (a), the polyolefin resin (b) and the hydrogenated block copolymer (c) is such that the polystyrene resin (a), The weights of the polyolefin resin (b) and the hydrogenated block copolymer (c) are
_A, W _B, when formed into a W _C, it is necessary that _{0.005 ≦ W C / (W A} + W B + W C) ≦ 0.25.

Here, when the weight W _C of the hydrogenated block copolymer (c) satisfies 0.005> W _C / (W _A + W _B + W _C ), the weight of the hydrogenated block copolymer in the resin composition is reduced. Coalescing (c)
Is small, and the effect as a compatibilizing agent is not sufficiently exhibited, so that the resulting resin composition has almost no improvement in oil resistance, impact resistance and the like. Also,
For _{W C / (W A + W} B + W C)> 0.25, the resin composition rigidity is lowered, properties derived from the polystyrene resin (a) and the polyolefin resin (b) is impaired. The weight WC of the hydrogenated block copolymer (c) is 0.1.
It is preferable that 025 ≦ W _C / (W _A + W _B + W _C ) ≦ 0.25. The polystyrene resin (a) and the polyolefin resin (b) in the resin composition of the present invention.
Is not particularly limited, but is usually W
_A / W _B = 95 / 5-5 / 95.

The resin composition of the present invention may contain a polyoxymethylene resin, a polyphenylene ether resin, a polyester resin, an acrylic resin, etc. as long as its properties are not impaired. Further, the resin composition of the present invention may contain a plasticizer such as process oil or polyethylene glycol. Furthermore, it is also possible to add an inorganic filler such as mica, talc, calcium carbonate, silica, kaolin, titanium oxide and the like.

Further, the resin composition of the present invention may contain, for the purpose of modifying it, glass fiber, carbon fiber, heat aging inhibitor, light stabilizer, antistatic agent, release agent, flame retardant, foaming agent, Pigments, dyes, brighteners and the like can be added.

The resin composition of the present invention can be prepared, for example, by melt-kneading the components using a kneader such as a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, or a roll. At this time, it is preferable that each component is dry-blended using a mixer such as a Henschel mixer or a tumbler before melt-kneading.

The resin composition thus obtained can be formed into various molded products by various conventional molding methods, for example, injection molding, blow molding, press molding, extrusion molding, calendar molding and the like. is there.

The resin composition of the present invention is excellent in moldability and secondary workability and gives a molded article excellent in impact resistance and chemical resistance. Starting with equipment and household electrical products, housings for various equipment, interior and exterior materials, mechanical parts, automobile parts, electrical parts, toys, various sporting goods, industrial parts, medical supplies,
It can be used in various fields such as daily necessities, miscellaneous goods, building materials and hollow molded products.

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Reference Example 1 (Production of hydrogenated block copolymer) In a pressure vessel equipped with a stirrer, 50 kg of cyclohexane, 1500 g of sufficiently dehydrated styrene, and 192 g of sec-butyllithium cyclohexane solution (10% by weight) were added.
And polymerized at 50 ° C. for 60 minutes.
Butadiene = 50/50 (weight ratio) mixed monomer 70
00g and add styrene for another 1500 minutes
In addition, after polymerization for 60 minutes, 16 g of ethylene oxide
And finally, methanol was added to terminate the polymerization, and a styrene-isoprene / butadiene-styrene type block copolymer having a hydroxyl group at the terminal (hereinafter referred to as S-
I / B-S-OH). Next, this SI / BS-OH was hydrogenated in cyclohexane using a Ziegler catalyst under a hydrogen atmosphere to obtain SI / BS-OH.
A hydrogenated product of BS-OH (hereinafter referred to as SEEPS-
OH). The obtained SEEPS-OH had a number average molecular weight (determined by GPC; in terms of polystyrene) of 49,300. According to the ¹ H-NMR spectrum, the styrene content of SEEPS-OH was 30% by weight, and the number of terminal hydroxyl groups per molecule was 0.78.
It was confirmed that the hydrogenation rate was 98.6%.

REFERENCE EXAMPLE 2 (Production of hydrogenated block copolymer) 50 kg of cyclohexane, 2000 g of sufficiently dehydrated styrene, and 64 g of a cyclohexane solution of sec-butyllithium (10% by weight) were added to a pressure-resistant vessel equipped with a stirrer. After polymerization at 60 ° C. for 60 minutes, 110 g of tetrahydrofuran was added, 6000 g of butadiene was added, polymerization was carried out for 60 minutes, 2,000 g of styrene was added, and polymerization was carried out for 60 minutes. After stopping, a block copolymer of styrene-butadiene-styrene type having a hydroxyl group at a terminal (hereinafter, abbreviated as SBS-OH) was synthesized. Next, this SBS-OH was hydrogenated in the same manner as in Reference Example 1 to obtain a hydrogenated product of SBS-OH (hereinafter, referred to as a hydrogenated product)
This is abbreviated as SEBS-OH). Obtained S
The number average molecular weight (based on GPC measurement, in terms of polystyrene) of EBS-OH was 155,300. Also ¹
According to the H-NMR spectrum, the obtained SEBS-OH
Has a styrene content of 40% by weight, a number of terminal hydroxyl groups per molecule of 0.82, a hydrogenation rate of 99.3%, and a 1,4-bond content of 4 in the hydrogenated polybutadiene block.
It was confirmed to be 0.2 mol%.

Reference Example 3 (Production of hydrogenated block copolymer) In a pressure vessel equipped with a stirrer, 50 kg of cyclohexane, 1500 g of sufficiently dehydrated styrene, and 120 g of a cyclohexane solution (10% by weight) of sec-butyllithium were used.
And polymerized at 50 ° C. for 60 minutes. Then, 250 g of tetrahydrofuran was added, 7000 g of isoprene was added, 60 minutes, and 1500 g of styrene was further added.
After polymerization for 1 minute, 17 g of ethylene oxide was added, and finally methanol was added to stop the polymerization, and a styrene-isoprene-styrene type block copolymer having a hydroxyl group at a terminal was synthesized. The obtained block copolymer was hydrogenated in the same manner as in Reference Example 1 to obtain a hydrogenated block copolymer (hereinafter abbreviated as HVSIS-OH). The number average molecular weight of the obtained HVSIS-OH (GP
By C measurement. Polystyrene equivalent. ) Was 78,100. According to the ¹ H-NMR spectrum, the styrene content of the obtained HVSIS-OH was 20% by weight,
The number of terminal hydroxyl groups per molecule was 0.65, the hydrogenation rate was 85.4%, and the number of 1,5 in the hydrogenated polyisoprene block was 1.
It was confirmed that the 4-bond content was 47.7 mol%.

Reference Example 4 (Production of hydrogenated block copolymer) In a pressure vessel equipped with a stirrer, 50 kg of cyclohexane, 1000 g of sufficiently dehydrated isoprene, and a cyclohexane solution of sec-butyllithium (10% by weight) 915
g is added, and polymerization is carried out at 50 ° C. for 60 minutes. Then, 4000 g of isoprene is added, and styrene is further added for 500 minutes.
After adding 0 g and polymerizing for 60 minutes, ethylene oxide 7
6 g was added, and finally methanol was added to stop the polymerization, and an isoprene-styrene type block copolymer having a hydroxyl group at a terminal was synthesized. The obtained block copolymer was hydrogenated in the same manner as in Reference Example 1 to obtain a hydrogenated block copolymer (hereinafter, abbreviated as EPS-OH). The obtained EPS-OH had a number average molecular weight (determined by GPC; in terms of polystyrene) of 88,500. From the ¹ H-NMR spectrum, the obtained EPS-OH had a styrene content of 50% by weight, the number of terminal hydroxyl groups per molecule was 0.92, and the hydrogenation rate was 97.
It was confirmed that it was 4%.

Reference Example 5 (Production of hydrogenated block copolymer) In a pressure vessel equipped with a stirrer, 50 kg of cyclohexane, 2000 g of sufficiently dehydrated styrene, and 64 g of sec-butyllithium cyclohexane solution (10% by weight) were added. After polymerization at 60 ° C. for 60 minutes, 110 g of tetrahydrofuran was added, 6000 g of butadiene was added, polymerization was carried out for 60 minutes, 2,000 g of styrene was added, polymerization was carried out for 60 minutes, and then methanol was added to stop the polymerization. A type of block polymer was synthesized. The obtained block copolymer was hydrogenated in the same manner as in Reference Example 1 to obtain a hydrogenated block copolymer (hereinafter, referred to as “hydrogenated block copolymer”).
This is abbreviated as SEBS). SEBS obtained
Has a number average molecular weight (determined by GPC and converted to polystyrene) of 155,800. In addition, ¹ H-NMR
The spectrum confirmed that the obtained SEBS had a styrene content of 40% by weight, a hydrogenation rate of 98.9%, and an amount of 1,4-bond in the butadiene block of 39.8 mol%.

Examples 1 to 5 and Comparative Examples 1 to 2 After the respective components were dry-blended according to the formulations shown in Table 1, the extruding temperature was 150 to 210 using a twin-screw extruder.
The extruded strand was melt-kneaded at a temperature of ° C., and the extruded strand was pelletized by a strand cutter to obtain a resin composition. The obtained resin composition was injection molded at 230 ° C. to prepare a test piece, and the flexural modulus as an index of rigidity and the Izod impact strength at 25 ° C. as an index of impact resistance were determined by the following method. It was measured. In addition, chemical resistance was evaluated by the following method. The results are shown in Table 1.

A specimen having a flexural modulus of 110 mm × 10 mm × 4 mm was prepared,
It was measured according to SK7203. ◎ Izod impact strength A test piece having a size of 63.5 mm × 12.7 mm × 3.1 mm was prepared, and the test piece was prepared according to the method described in JIS K7110.
Measured in ° C. The greater the value of the Izod impact strength, the better the impact resistance. ◎ Chemical resistance A test piece of 110 mm × 10 mm × 4 mm was prepared, and n-
After being immersed in heptane for 1 hour, the flexural modulus was measured in accordance with JIS K7203, and the retention to the flexural modulus before immersion in n-heptane was calculated according to the following equation. Retention (%) = (flexural modulus after immersion in n-heptane) / (flexural modulus before immersion in n-heptane) × 1
00 The greater the value of the retention, the better the chemical resistance.

[0035]

[Table 1]

As is clear from Table 1, the resin composition of the present invention containing the hydrogenated block copolymer (c) having a hydroxyl group at the terminal is a molded article having excellent impact resistance and chemical resistance. It turns out to give.

[0037]

According to the present invention, there is provided a resin composition which gives a molded article having excellent impact resistance and chemical resistance.

Claims (1)

[Claims] 1. A polymer block A comprising (a) a polystyrene-based resin, (b) a polyolefin-based resin and (c) an aromatic vinyl compound, at least one polymer block A, and a conjugated diene compound, which is derived from the conjugated diene compound. A resin composition comprising a hydrogenated block copolymer having at least one polymer block B in which at least 70% of the carbon-carbon double bonds are hydrogenated, and having a hydroxyl group at a terminal, When the weights of (a) a polystyrene-based resin, (b) a polyolefin-based resin, and (c) a hydrogenated block copolymer in the composition are respectively represented by W _A , W _B , and W _C , 0.005 ≦ W _C / (W _A + W _B + W _C ) ≦ 0.25.